What I noticed when using the Universal GUI on mobile, if you press the back button that it exits the application. This is, at least for me, unexpected. I would have expected that if I press the back button, that it would go back to the previous screen (if possible).
Example, I select a row in a list, go to the form to see some information. Then when I press 'back', I would like the List to be opened again so I can select a different row if desired.
From my understanding the Universal GUI is a single page application but I hope there's a way to manipulate the way the back button responds.